tgbotapi/tgbotapi.core/src/jvmMain/kotlin/dev/inmo/tgbotapi/utils/passport/DecryptionContextRealizatio...

40 lines
1.5 KiB
Kotlin

package dev.inmo.tgbotapi.utils.passport
import dev.inmo.micro_utils.crypto.decodeBase64
import java.security.KeyFactory
import java.security.interfaces.RSAPrivateKey
import java.security.spec.PKCS8EncodedKeySpec
import javax.crypto.Cipher
private val regexToRemoveFromKey = Regex("(-----(BEGIN|END) ((?:.*? KEY)|CERTIFICATE)-----|[\\s])")
/**
* @param key PKCS8
*/
class PKCS8Decryptor (key: String): Decryptor {
private val privateKey: RSAPrivateKey = KeyFactory.getInstance("RSA").generatePrivate(
PKCS8EncodedKeySpec(key.replace(regexToRemoveFromKey, "").decodeBase64())
) as RSAPrivateKey
private val chunkSize: Int = privateKey.modulus.bitLength() / 8
override fun ByteArray.decrypt(): ByteArray {
return Cipher.getInstance("RSA/ECB/OAEPWITHSHA-256ANDMGF1PADDING").run {
init(Cipher.DECRYPT_MODE, privateKey)
(0 until size step chunkSize).flatMap {
val firstIndex = it
val lastIndexExclusive = if (it + chunkSize > size) {
size
} else {
it + chunkSize
}
doFinal(copyOfRange(firstIndex, lastIndexExclusive)).toList()
}.toByteArray()
}
}
}
fun Decryptor(key: String) = PKCS8Decryptor(key)
inline fun <T> doWithDecryptor(decryptor: Decryptor, crossinline block: Decryptor.() -> T) = decryptor.run(block)
inline fun <T> doWithDecryptor(key: String, crossinline block: Decryptor.() -> T) = doWithDecryptor(Decryptor(key), block)